// Copyright (c) 2024 The Bitcoin developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

// This service worker can be customized!
// See https://developers.google.com/web/tools/workbox/modules
// for the list of available Workbox modules, or add any other
// code you'd like.
// You can also remove this file if you'd prefer not to use a
// service worker, and the Workbox build step will be skipped.

import { clientsClaim } from 'workbox-core';
import { ExpirationPlugin } from 'workbox-expiration';
import { precacheAndRoute, createHandlerBoundToURL } from 'workbox-precaching';
import { registerRoute } from 'workbox-routing';
import { StaleWhileRevalidate } from 'workbox-strategies';

clientsClaim();

// Precache all of the assets generated by your build process.
// Their URLs are injected into the manifest variable below.
// This variable must be present somewhere in your service worker file,
// even if you decide not to use precaching. See https://cra.link/PWA
precacheAndRoute(self.__WB_MANIFEST);

// Set up App Shell-style routing, so that all navigation requests
// are carried out with your index.html shell. Learn more at
// https://developers.google.com/web/fundamentals/architecture/app-shell
const fileExtensionRegexp = new RegExp('/[^/?]+\\.[^/]+$');
registerRoute(
    // Return false to exempt requests from being carried out by index.html.
    ({ request, url }) => {
        // If this isn't a navigation, skip.
        if (request.mode !== 'navigate') {
            return false;
        } // If this is a URL that starts with /_, skip.

        if (url.pathname.startsWith('/_')) {
            return false;
        } // If this looks like a URL for a resource, because it contains // a file extension, skip.

        if (url.pathname.match(fileExtensionRegexp)) {
            return false;
        } // Return true to signal that we want to use the handler.

        return true;
    },
    createHandlerBoundToURL(process.env.PUBLIC_URL + '/index.html'),
);

// An example runtime caching route for requests that aren't handled by the
// precache, in this case same-origin .png requests like those from in public/
registerRoute(
    // Add in any other file extensions or routing criteria as needed.
    ({ url }) =>
        url.origin === self.location.origin && url.pathname.endsWith('.png'), // Customize this strategy as needed, e.g., by changing to CacheFirst.
    new StaleWhileRevalidate({
        cacheName: 'images',
        plugins: [
            // Ensure that once this runtime cache reaches a maximum size the
            // least-recently used images are removed.
            new ExpirationPlugin({ maxEntries: 50 }),
        ],
    }),
);

// This allows the web app to trigger skipWaiting via
// registration.waiting.postMessage({type: 'SKIP_WAITING'})
self.addEventListener('message', event => {
    if (event.data && event.data.type === 'SKIP_WAITING') {
        self.skipWaiting();
    }
});

// Any other custom service worker logic can go here.
addEventListener('fetch', event => {
    event.respondWith(
        (async () => {
            if (
                event.request.mode === 'navigate' &&
                event.request.method === 'GET' &&
                self.registration.waiting &&
                (await self.clients.matchAll()).length < 2
            ) {
                self.registration.waiting.postMessage('skipWaiting');
                return new Response('', { headers: { Refresh: '0' } });
            }
            return (await caches.match(event.request)) || fetch(event.request);
        })(),
    );
});
